Field of the Invention
The present invention relates to an electrophotographic photosensitive member, and an electrophotographic apparatus and a process cartridge having the electrophotographic photosensitive member.
Description of the Related Art
Since a surface layer of an electrophotographic photosensitive member is repeatedly subjected to stress by a series of electrophotographic processes such as charging, exposure, development, transfer, and cleaning, abrasion resistance and chemical stability are required.
As a method for improving abrasion resistance, a method in which a curable resin is contained in the surface layer of the electrophotographic photosensitive member can be mentioned. However, when a surface layer having high abrasion resistance is installed, the surface layer is hard to wear, so that it is difficult to refresh a surface of the surface layer, and chemical deterioration is likely to be accumulated on the surface of the surface layer. Chemical deterioration is a phenomenon that a hole transport material (hole transporting compound) present in the surface layer undergoes a chemical change due to the stress caused by the series of electrophotographic processes described above. The chemical change of the hole transport material sometimes causes a phenomenon that an electrophotographic image output under a high temperature and high humidity environment becomes blurred (hereinafter, also referred to as image deletion). Therefore, in order to suppress image deletion, there is a need to suppress the chemical change of the hole transport material.
As a method for improving chemical stability of the hole transport material, there is a technology of allowing an additive to be contained together with the hole transport material in the surface layer. Japanese Patent Application Laid-Open No. 2007-11005 discloses a technology of alleviating the image deletion by adding a specific fluorine atom-containing monomer having a polymerizable functional group to a surface layer. Japanese Patent Application Laid-Open No. 2007-11006 discloses a technology of allowing a surface layer to have a specific fluorine atom-containing hole transport monomer. Japanese Patent Application Laid-Open No. 2007-272191, Japanese Patent Application Laid-Open No. 2007-272192, and Japanese Patent Application Laid-Open No. 2007-279678 disclose technologies of alleviating image deletion by adding a specific amine compound to a surface layer. Japanese Patent Application Laid-Open No. 2008-70761 discloses a technology of alleviating image deletion by adding a specific siloxane compound having a specific polymerizable functional group to a surface layer. Japanese Patent Application Laid-Open No. H4-315159 and Japanese Patent Application Laid-Open No. H6-48999 disclose stilbene derivatives having a specific substituent.
Technologies using compounds of Japanese Patent Application Laid-Open No. 2007-11005 and Japanese Patent Application Laid-Open No. 2007-272191, Japanese Patent Application Laid-Open No. 2007-272192, Japanese Patent Application Laid-Open No. 2007-279678, and Japanese Patent Application Laid-Open No. 2008-70761 are technologies for alleviating exposure of stress described above to a hole transport material, and are not technologies for improving chemical stability of the hole transport material itself. Further, in a technology of Japanese Patent Application Laid-Open No. 2007-11006, an object to allow a surface layer to have low surface energy is disclosed, but Japanese Patent Application Laid-Open No. 2007-11006 does not disclose deterioration nor electrical properties during long-term use under a specific environment. Further, compounds of Japanese Patent Application Laid-Open No. H4-315159 and Japanese Patent Application Laid-Open No. H6-48999 do not have a polymerizable functional group and do not form a crosslinked structure as in the present invention. Therefore, these compounds are not suitable for being applied to a high-durability electrophotographic photosensitive member.
Recently, durability of an electrophotographic photosensitive member has been significantly increased, and there is an increasing demand for alleviating image deletion. In order to alleviate image deletion, there is a need to improve chemical stability of the hole transport material itself in addition to alleviating exposure of stress described above. Further, there is a need to improve potential properties in a case of using a high-durability electrophotographic photosensitive member for a long period of time under a specific low humidity environment.
Therefore, an object of the present invention is to provide an electrophotographic photosensitive member which has high durability, satisfies electrical properties, and in which image deletion is satisfactorily alleviated, and an electrophotographic apparatus and a process cartridge having the electrophotographic photosensitive member.